1. Technical Field
This disclosure relates to an image forming apparatus.
2. Description of the Related Art
Image forming apparatuses are used as printers, facsimile machines, copiers, plotters, or multi-functional devices having, e.g., two or more of the foregoing capabilities. For example, there is known an image forming apparatus, such as a label printer for printing on a print medium having an adhesive face with no release sheet adhering on the adhesive face (hereinafter also referred to as “linerless label sheet” or non-separate label), such as a tape or an unmounted label sheet, and cutting the print medium into a desirable length after printing to obtain a print medium piece (hereinafter also referred to as a “label piece”), or the like.
For example, an image forming apparatus includes a print head for printing a desirable mark on a print face of a label, a print roller disposed near the print head to press the label toward the print head during printing, a separation bar disposed at an interval from the print roller, and an endless belt to be moved around the print roller and the separation bar. The image forming apparatus has a structure in which the label adheres to the belt in the print head and is conveyed to the separation bar, and the label is separated from the belt in the position (JP-H07-172006-A).
In a case in which a roll-shaped print medium is used, when an image forming operation is carried out and a print medium is conveyed to a cutting position and cut into a label piece, an image is not formed in an area opposing an image forming unit. As a result, if the image forming operation is restarted with the print medium placed in the exact position, the print medium would be wasted.
Hence, before the image forming operation is restarted or when there is no image to be formed subsequently, a returning operation may be performed to return a leading end of the print medium to a position upstream from the image forming unit in a conveyance direction of the print medium, thus reducing the waste of the print medium.
However, for such a configuration, in particular, if a slack occurs in a print medium, such as a linerless label sheet, having an exposed adhesive face, different portions of the adhesive face might adhere to each other or the adhesive face may adhere to a different member, thus hampering the returning operation.
Additionally, in a case in which the print medium is conveyed by paired rotors, the adhesive face might adhere to one of the rotors disposed on the adhesive face side in a nipping portion between the paired rotors. As a result, the print medium might be wound around the rotor, thus hampering the returning operation.